1. Field of the Invention
The present invention relates to systems and methods for sorting mail.
2. Discussion of the Background
The United States Postal Service (USPS) allows large volume mailers of flat mail (i.e., mail that is generally flat shaped, but larger than typical letter-sized mail) to prepare a mailing in a number of formats and sequences. Typically, flat mail (or “flats”) are prepared in bundles. Bundles are created to allow flats that are destined for the same carrier route or zone to be processed together.
There are a number of preparation schemes that mailers can use in preparing bundles of flats, and each scheme has a mailing cost associated with it. The following is an example of some of the various, schemes in which mailers can prepare bundles of flats. The first example scheme is referred to as “3-digit.” In the 3-digit scheme, all mail within the bundle is addressed to a delivery point within a given 3-digit postal zone (this refers to the 1st three digit of a zip code, i.e. 210xx). The mail within the bundle will be distributed to a number of facilities and carrier routes within that zone.
The second example scheme is referred to as “5-digit .” In the 5-digit scheme, all mail within the bundle is addressed to a 5-digit zone. The third example scheme is referred to as “carrier route”. In the carrier route scheme, the bundle contains only mail for a specific carrier within a given 5-digit zone. The last example scheme is referred to as “Line-of-Travel (LOT) and/or Carrier Sequenced (CS).” In the LOT/CS scheme, the bundles have been prepared such that the mail within the bundles is in a sequence for a specific carrier within a zone. LOT mail contains mail in either ascending or descending order for addresses on streets in a close approximation of how the carrier actually delivers the mail. Carrier Sequence mail is prepared in exactly the sequence that the carrier delivers the mail.
Each above scheme is processed by the USPS differently and has an associated processing cost. 3-digit mail is usually cross-docked through postal facilities as a bundle until it arrives at the processing center that serves the 3-digit zone. The bundle is then opened and processed to a 5-digit level and delivered to the post office that serves that 5-digit zone.
5-digit bundles are cross-docked all the way to the processing center that serves the 5-digit zone. Depending on the processing center operations, the bundle may be delivered to the local post office that delivers the mail or may be processed down to the carrier level (separating the mail to the carrier within the deliver office so that the carrier doesn't have to separate the mail). Carrier Route, LOT and Carrier sequence mail are all cross-docked directly to the local post office that delivers the mail.
In all cases, the local carrier “cases” the flats for his route to prepare them for delivery. That is, as carriers receive their flats for the day, they sort them into what is referred to as “carrier walk sequence” or “delivery point order”.
More specifically, casing a set of mail refers to the process of placing each piece of mail in the set into the appropriate cubbyhole in a matrix of cubbyholes. Each cubbyhole in the matrix corresponds to one delivery point on the carrier's route. Thus, by placing each piece of mail into its corresponding cubbyhole and then removing the mail from the cubbyholes in the order in which the carrier traverses his mail route, the carrier can create a bundle of mail that is in carrier walk sequence. Accordingly, the result of the casing operation is that all mail for each address or delivery point in the carrier's route is stacked together in order of delivery point. Thus, when the carrier arrives at a particular delivery point on his/her route, the carrier can simply remove from the “top” of his/her bundle of mail the mail addressed to the particular delivery point.
Various metrics are used to determine the rate at which mail can be cased. Mail presented to the carrier in carrier walk sequence can be cased much faster than purely random mail. Typically a carrier cases random mail at 8 pieces per minute and sequenced mail at 18 pieces per minute. In order to facilitate more productive casing operations, the USPS will pass a portion of the savings created by sequenced mail back to the mailers in incentives (i.e. mailers will be charged less per piece of mail if they prepare a sequenced mailing rather than a random mailing).
These mailing standards and incentives are based in a large part on the principle that the carrier will sequence (e.g., case) mail at the delivery unit and have been tailored to account for the automation and mechanization used in postal facilities to route the mail through the postal network.
In addition to the flats described above, other mail may be automatically processed and presented to the local carriers in the delivery order of their route (i.e., delivery point order). This process is referred to as delivery point sequencing. On many routes, a large portion of a carrier's letter mail can arrive at the delivery unit in this form. Letter mail that has not been delivery point sequenced (“residual mail”) is cased along with the flats.
Carriers may also receive bulk mailings (high density and/or saturation mailings) that are to be delivered to a large percentage, if not all, of the delivery points on their route. These mailings are either presented to the carrier in delivery point order or do not have a specific address on them allowing the carrier to deliver them to the appropriate address without needing to check for the address on the mail piece (in these cases, the non-addressed mailing will be delivered along with an arrested card that serves as the carriers cue to include a high density piece of mail at that address). In other cases, all of the delivery points, or residences on the route receive one of the high-density pieces and no card is required.
After their in-office time, carriers load their vehicles and begin making deliveries on their routes. Usually, a carrier will have three bundles of mail that they take onto the street with them: (1) sequenced letters that were automatically prepared in processing centers, (2) cased letter and flats that they sorted in the delivery unit casing operation and (3) sequenced flats prepared by mailers. As the carriers arrive at each delivery point, they pull the appropriate mail from each bundle. This process is referred to as ‘fingering the mail’ as the carriers flip through the end of each bundle until they have accrued all of the mail for that delivery point in the bundle and then move to the next bundle. Carriers can, and do, facilitate this operation by folding their cased mail in a ‘U’ shape (using the flats mail to serve as a holder for the letter mail) when they pull it down from the cases. This allows a carrier to visually recognize a batch of mail for delivery point during the delivery process.
Recently, automation capabilities have been introduced into postal facilities that have enabled new and more efficient ways of handling the mail. More specifically, the use of high speed flats automation equipment and the development of automated sequencing equipment have enabled the USPS to consider moving the majority of delivery unit mail handling into the processing centers. In this new paradigm, mail would be processed to either carrier level, or completely sequenced at carrier level, before it arrives at the local delivery office. This approach would remove the majority of manual labor involved in preparing the mail for delivery and allow delivery offices to run more efficiently.
While these automated systems may reduce costs by reducing the labor involved with casing the mail, it is important that they do not increase costs elsewhere in the mail system. It is also important that they be environmentally friendly.
One such automated system is described in U.S. patent application Ser. No. 20030155282, filed on Feb. 15, 2002, the contents of which are incorporated herein by reference. However, the system described therein relies on environmentally unfriendly bundling machines. Other drawbacks and disadvantages also exist.
What is desired, therefore, is an economically efficient and environmentally friendly system and method for processing mail that reduces the manual labor involved with casing and delivering mail.